The molecule, known as SLR14, is a simple, easy-to-make RNA loop that can trigger the production of interferons, a group of proteins produced by immune cells that play a key role in the body’s innate or initial response to infection.
Several studies have shown that COVID-19 patients who produce high levels of interferons have much better results than those with low interferon levels in the early stages of infection.
The treated mice also responded well to numerous variants of SARS-CoV-2, the virus that causes COVID-19, including the Delta variant, which is currently the prevalent strain of the virus in the United States, according to a new report released on November 10th. In Experimental Medicine.
If clinical trials in humans confirm the efficacy of SLR14, a relatively inexpensive compound could help reduce COVID-19 cases in low-income countries where vaccine availability is limited, the researchers say. It can also provide important benefits to immunocompromised individuals who are unable to generate sufficient amounts of antibody-producing B cells and virus-killing T cells.
“SLR14 thus holds great promise as a new class of RNA therapeutic agents that can be used as antiviral drugs against SARS-CoV-2,” he said. Akiko Iwasaki, Waldemar Von Zedtwitz Professor of Immunobiology and Molecular, Cell and Developmental Biology in Yale and co-author.
Iwasaki added: “Furthermore, because this RNA-based therapeutic approach is simple and diverse, our research will facilitate pandemic preparedness and response to future respiratory pathogens that are sensitive to type I interferons.”
Typically, vaccines, such as those that fight COVID-19, carry harmless viral elements that trigger the production of T and B cells in the body’s adaptive immune system, which is able to recognize previous pathogens and elicit a targeted response. Treatments such as monoclonal antibodies also tend to mimic this later-stage immune response.
However, for new research, a group led by the first author Tianyang Mao, a graduate student at Iwasaki Laboratory, investigated whether compounds such as SLR14 could activate the innate immune system and protect against viral infections, including COVID-19.
In the experiments, the researchers found that one dose of the compound was enough to protect mice from serious disease and death, worked against several variants, and could even eradicate the virus from mice with a chronic infection.
“The results of natural immune activation in eliminating a chronic infection were surprising and spectacular,” Iwasaki said.
The patent rights for SLR14 and related compounds are owned by RIGimmune, the co-founder of Iwasaki and Iwasaki. Anna Pyle, Yale, professor of molecular, cellular, and developmental biology and co-author of this study, is looking for new agents that can control a variety of pathogens.
Source: The Nordic Page